EFFECTS OF DIATOMS ON THE GROWTH OF FUCUS-SPIRALIS GERMLINGS IN CULTURE

In culture, the presence of the diatom Navicula incerta Grun. adversely influenced the growth and even the survival of germlings of Fucus spiralis. The effects increased with the abundance of the diatoms. Another diatom Berkeleya rutilans (Trent.) Grun. had similar, although less marked effects on growth, but did not appear to impair the health of the germlings. Simply diluting the culture medium to 1/1 Oth or l/20th of its usual concentration greatly inhibited the growth of the diatoms, but not that of F. spiralis. This method of reducing contamination is recommended where it is not feasible to eliminate diatoms by other means. The effects of lower nutrient concentrations on the growth of apical hairs in F. spiralis is also discussed. © 1979, Walter de Gruyter. All rights reserved.